Vaska complexes

Silylation of arenes was reported to take place with rhodium and iridium complexes as the catalyst. The Vaska complex effects the reaction of benzene with pen-tamethyldisiloxane,230 whereas [RhCl(CO)(PMe3)2] catalyzes the formation of C—Si bonds under irradiation231 [Eq. (10.39)] 232... 

An early and popular complex, [IrCl(CO)(PPh3)2], called the Vaska complex,113 and its derivatives can be used for the hydrogenation of unsaturated hydrocarbons.26,31... 

The X-ray structure of 170 has been reported (56). Generally only unsubstituted sp -hybridized carbon atoms of butadiene ligands are attacked by HFA (133). Different behavior has been found in the reactions of iridium complexes with HFA. With tris(triphenylphosphane)nitrosyliridium the geometry is retained [Eq. (139)] (63). However, the Vaska complexes lead to... 

As a first interesting example, Stang and Critell reported in 1990 the alkynylation of Vaska complexes 16 and 17 with alkynyliodonium triflates at room temperature in excellent yield (Scheme 9) [88]. Using bis-alkynyliodonium salts, the method could be extended to the formatiOTi of binuclear complexes such as 18 and 19, or even trinuclear systems [89-91]. These conjugated polymetallic complexes have great potential for applications in nonlinear optics, organic conductors, or liquid crystals. 

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